Lost 30hp 6k+ rpm

[pulpmelon_r]

What are the specs on your motor Luke?

The weather has been warm and humid for sept / oct you might be pinking and the ECU is pulling ign adv ?

 

[tricker_luke]

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[AP-Performance]

The specs are on a previous post in this thread.
Datalog is not showing any knock and the threshold is not being reached at any point.

An interesting thing I noticed was that where my losses occur the af ratio drops down to as low as 11.5, too rich.
My tuner had tuned it to around 12.7 WOT I think he said, and I have checked the exhaust and intake incase they were restricted.
The only other possible cause could be a faulty fuel regulator giving too much fuel at certain revs, or is that unlikely?

Unlikely the regulator is at fault, normally when they give bother it would effect fuelling right across the board not just at a specific rpm range. Have you checked the ignition system? a slight missfire will give rich readings and down on power...could be down to one faulty coil.

 

[tricker_luke]

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[tricker_luke]

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[leejw87]

Oh, another symptom that has happened a few times now over the last few weeks is that the engine took about 5 seconds to crank over, then when it fired the revs built up slowly and it stunk of petrol.

Poor starting can be caused by low fuel pressure but your injectors will still inject the required amount of CC's to start the vehicle
but it will take a little longer as the pressure is low.. thats why you got a fuel smell when it did start as there was excess fuel in the cylinders.

Get your engine builder to check the Fuel pressure. if the fuel pressure is ok then that is one thing you have eliminated.

Out of interest did you increase the Compression ratio?

 

[AP-Performance]

I haven't checked the ignition really. How would I check for a faulty coilpack other than checking if the plug is sparking, or is that the only way?

I just can't wait to get this all fixed then I should have one quick 2.2l cammed engine!

Check each coil with a multimeter using ohm's test(between +/- of coil) if one coil give's a reading not similar to the rest it would be suspect. I assume you have tried a new set of spark plugs?

 

[eg9_dc2]

have you tried switching back to the stock ecu...then compare the dyno graphs,?? if your losing even more power than a stock ecu is mapped for then youl know it's something mechanical...??

 

[Stoo]

have you tried switching back to the stock ecu...then compare the dyno graphs,?? if your losing even more power than a stock ecu is mapped for then youl know it's something mechanical...??

This is a ridiculous idea.
Please don't even contemplate this.
Running a STD ECU/Map with this state of tune could be catastrophic.

 

[eg9_dc2]

faulty fuel pump?? fuel filter??

 

[eg9_dc2]

****missed the post about the modified engine...stupid phone.****

lol the ecu would be a bad idea..

 

[eg9_dc2]

if his maps ok...it could be..dare I say it something faulty in the head..spring maybe? Aftermarket cams sometimes require aftermarket valves/springs....when are the vtec cams mapped to engage? ...it might have been all hunky dorey when freshly built and mapped but something maybe have been damaged in the head after a while causing the power loss....??...

 

[eg9_dc2]

you can also read your plugs...see if they are running lean/rich to figure if it's an air intake problem,over fueling/underfueling and take it from there??

 

[tricker_luke]

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[tricker_luke]

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[coyote_dc5]

I compared fuel pressure to coyote_dc5 and they were similar, around 5 i think of whichever unit its measured in. I can recheck this anyway, or is kmanager not the most accurate of readings?

5.7KPa

 

[leejw87]

Oh and yes I have higher compression pistons, I think they are 12.1.

Does the car feel like it's running rough in any way (hesitation, misfire etc) and does the car feel under powered when driving?

 

[tricker_luke]

Hesitation and juddering yea but more low down and the tuner is going to sort that side of it out, but it's trying to understand how it is now 30hp and 15lb down at the wheel on the same dyno.
And it starts at exactly 5k, which is exactly the point the af drops rich, down to about 11.5

 

[raz786]

Hesitation and juddering at low revs ( about 3000-4000rpm) could be the vtc sensor. IIRC that can also affect cam angles?

 

[leejw87]

Hesitation and juddering yea but more low down and the tuner is going to sort that side of it out, but it's trying to understand how it is now 30hp and 15lb down at the wheel on the same dyno.
And it starts at exactly 5k, which is exactly the point the af drops rich, down to about 11.5

It's sounds to me' like you have more of a component fault rather than a map fault specially if you have hesitation.

Main things to check would be :

Sparks Plugs - gaps, burnt, correct type etc

Coils - resistance reading make sure there's no internal shorts ( and as said by ap performance make sure the ohms reading is the same on each coil.

Fuel Pressure - should be a constant pressure.... too high if it's running rich)
Too low if it's running lean.

Blocked air filter - too much fuel not enough air)

General look around no split breathers or air leaks etc drawing in unmetered air.